Mount Prospect, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

045
FXUS63 KLOT 190900
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
300 AM CST Mon Jan 19 2026

.KEY MESSAGES...

- Scattered snow showers and areas of blowing snow this morning.

- Bitterly cold conditions this morning with wind chills 20
  below to 25 below zero. Then continued very cold through
  Tuesday morning.

- A clipper system is expected to bring accumulating snow to
  parts of the area Tuesday night into Wednesday morning,
  especially for areas north of I-80.

- Two cold fronts, Wednesday night and Thursday night, may each
  bring a period of light snow or snow showers.

- Another period of bitterly cold temperatures is possible
  Thursday night into this weekend.

&&

.DISCUSSION...
Issued at 300 AM CST Mon Jan 19 2026

The arctic front has pushed through the cwa and with its
arrival were heavy snow showers with continued scattered snow
showers across parts of the Chicago metro area. While these are
expected to continue to slowly shift southeast and weaken
through daybreak, upstream obs show many locations reporting
2-5sm vis with snow showers/flurries and likely continued
blowing snow. Planning to have scattered snow showers and areas
of blowing snow this morning and with flurries possibly
continuing all day. Northwest winds gusting as high as 40 mph
through daybreak will begin to slowly diminish later this
morning into this afternoon.

Current precip and cloud cover has slowed the temp drop
slightly early this morning but expected low temps in the low
single digits for much of the area, a few degrees below zero
across the northwest cwa still appear on track, with the low
temps perhaps occurring after sunrise. Combined with the winds,
wind chills in the 20 below to 25 below zero range still on
track and no changes planned to the cold weather advisory. High
temps today will struggle back into the mid/upper single digits,
perhaps low teens across the south. Wind chills will remain
below zero through Tuesday morning. Similar low temps are
expected Tuesday morning, low single digits, near zero in the
northwest cwa, but with much lower winds, wind chills Tuesday
morning look to be in the 5 below to 10 below zero range.

There is another weak wave moving across the area this evening
that the models remain dry with. Expect an increase in cloud
cover and there is the potential for some flurries, maybe a few
snow showers with this wave, but confidence too low to include
mention at this time. A fast moving area of high pressure will
then cross the area Tuesday morning.

The models have remained in overall good agreement with a
clipper moving across the region Tuesday night into Wednesday
morning. Though the most recent trend is for this system to
arrive sooner with snow spreading across northwest IL Tuesday
evening and then across much of northern IL, north of I-80 after
midnight. Blended guidance has increased considerably, now well
into the 80% range and qpf is now trending in the 0.10 to 0.15
range across far northern IL. As a result, a swath of 2-3 inches
is possible near the IL/WI state line with amounts lowering
further south with perhaps a rather sharp cutoff to the southern
edge of the snow. While most of the falling snow could be done
by the Wednesday morning rush hour, untreated roads will likely
be snow covered for the commute.

A cold front is then expected to move across the area Wednesday
evening, possibly into early Thursday morning. While not as
strong as the cold front this morning, there could be another
period of light snow or snow showers associated with this cold
front. In between the clipper Tuesday night and this cold
front Wednesday night, high temps Wednesday may briefly
moderate in the upper 20s north to possibly lower/mid 30s south.

The models and their ensembles have taken a turn to much colder
and drier for late week into this weekend. Still several days
away but the arctic high pressure building across the northern
Plains and Great Lakes region Thursday night into Friday may
send another strong arctic cold front across the area Thursday
afternoon or Thursday evening and another period of snow or
snow showers would be possible if this materializes.

Blended guidance is now significantly colder for Thursday night
into Saturday with subzero lows areawide Saturday morning with
wind chills in the 20 below to 30 below zero range. While there
is increasing confidence for this, confidence is still low for
these specifics and there is still quite a bit of uncertainty
for this weekend into early next week. cms

&&

.AVIATION /06Z TAFS THROUGH 12Z TUESDAY/...
Issued at 1105 PM CST Sun Jan 18 2026

Aviation messages:

- Arctic front moves across the terminals through 07-09z with
  strong northwest wind shift and gusts around 30-35 kts.

- Scattered wind-whipped snow showers expected as the front
  passes. Threat for localized sharp vsby reductions and quick
  additional accumulations near a half inch.

- MVFR cigs and intermittent snow showers/flurries through the
  night and likely through midday Monday.

- Low confidence on return to VFR conditions Monday afternoon.
  Small chance for flurries/light snow Monday afternoon and
  evening.

A strong arctic cold front will be pushing through the Chicago-
area terminals through 07-09z resulting in increasing
northwesterly winds gusting around 30-35 kts. Accompanying the
front will be an area of scattered wind-whipped snow showers,
the most robust of which are resulting in sharp but brief vsby
reductions down to around a half mile, gusts up to 45 mph, and a
quick half inch or so of snow accumulation. Coverage of these
showers is such that the most intense portions may not directly
impact the airfields, but is sufficient to justify TEMPO groups
with IFR vsbys.

Once this activity passes, light snow showers/flurries will likely
persist intermittently through much of Monday morning with
periods of 4-5 sm vsbys possible as the arctic airmass settles
overhead. While there is some potential for BLSN, given the
limited snowpack and snowfall from earlier this evening,
confidence in prevailing BLSN at the terminals was too low to
include in the TAFs.

VFR cigs may return sometime Monday afternoon, although confidence
in this is low, with some potential that MVFR cigs just linger
through the afternoon and evening. Winds will remain blustery
through Monday evening but will gradually diminish with time. There
is a small potential for another period of flurries late Monday
afternoon and evening, but the main signal for this remains north of
the Wisconsin state line, with no mention in the current TAFs.

Carlaw

&&

.MARINE...
Issued at 225 PM CST Sun Jan 18 2026

The gale warning remains in effect from midnight tonight into
Monday morning for all of the IL and IN nearshore waters.

A heavy freezing spray warning remains in effect for the
nearshore waters east of Gary, IN.

A strong arctic cold front will move across the area tonight,
bringing a period of gale force winds between 35 and 40 knots.
These strong winds will slowly diminish on Monday with gales
ending across the IL nearshore Monday morning and then across
the IN nearshore Monday afternoon. Very cold temperatures will
spread across the area behind this cold front and combined with
the high waves, heavy freezing spray is expected across parts of
the IN nearshore waters, mainly east of Gary, IN. Offshore winds
and a decent amount of ice formation along the Illinois
nearshore over the past day precludes the inclusion of a Heavy
Freezing Spray Warning west of Gary, IN.

cms/Kluber

&&

.HYDROLOGY...
Issued at 126 PM CST Sun Jan 18 2026

Area hydrographs and ice spotter reports confirm that ice
continues to develop and spread across areal rivers. Localized ice
jams are already present along the Rock and Des Plaines rivers.
Continued cold temperatures tonight and Tuesday will cause ice
to continue growing.

After a brief warm-up in temperatures to above 20 degrees on
Wednesday, another push of bitterly cold temperatures may arrive
as early as Friday. As a result, the threat for ice jams
including localized flooding will increase further toward the
end of the week.

- NWS Chicago

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Cold Weather Advisory until noon CST today for ILZ003-ILZ004-
     ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-ILZ012-ILZ013-ILZ019-
     ILZ020-ILZ021-ILZ023-ILZ032-ILZ033-ILZ039-ILZ103-ILZ104-
     ILZ105-ILZ106-ILZ107-ILZ108.

IN...Cold Weather Advisory until noon CST /1 PM EST/ today for
     INZ001-INZ002-INZ010-INZ011-INZ019.

LM...Gale Warning until noon CST today for Winthrop Harbor IL to
     Gary IN.

     Gale Warning until 3 PM CST this afternoon for Gary to Burns
     Harbor IN-Burns Harbor to Michigan City IN.

     Heavy Freezing Spray Warning until 9 PM CST this evening for
     Gary to Burns Harbor IN-Burns Harbor to Michigan City IN.

&&

$$

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